Info from Nial Moores of Birds Korea:
As background to the South Korean outbreaks, the following published information on AI sampling of wild bird populations in South Korea (provided today by Dr. Lee Hansoo), is especially useful:
Kim (2006) contains the following results of wild bird surveillance activity.
2003-04 winter: Tested 5,460 fecal samples, isolate 26 LPAI
2004-05 winter: Tested 3,970 fecal samples, isolate 34 LPAI
2005-06 winter: Tested 4,415 fecal samples, isolate 31 LPAI
2005-06 winter along DMZ area: Tested 1,900 fecal samples, isolate 46 LPAI
National Veterinary Research and Quarantine Service (NVRQS) teams tested the fecal sample of waterfowl in various areas since the 2003 AI outbreak, but they isolated only LPAI virus.
(During the current outbreak period, the NVRQS team apparently did not yet find any HPAI virus among the collected waterfowl samples.)
Reference:
Kim, Yong Ju. 2006. The characteristics of avian influenza virus by the active surveillance among wild birds. Proceedings of the epidemiological characteristics of HPAI and wild bird surveillance activity. pp 19-31. National Veterinary Research & Quarantine Service.